JPH0736984B2 - Manual bolt tightening tool - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bolt tightening tool for tightening a bolt having a tip whose tip is sheared with a constant torque.

[0002]

2. Description of the Related Art Conventionally, there is a fastener shown in FIG. 3 as such a fastener, and the fastener has a first stage planetary gear mechanism (1) and a second stage planetary gear mechanism (1a) in a housing (2). The internal gears (14) and (14a) of the two planetary gear mechanism to the housing (2)
Formed on the inner surface of.

The input shaft (10) driven by the manual handle (8) is connected to the sun gear (11) of the first stage planetary gear mechanism (1), and the planetary gear support frame (13) of the planetary gear mechanism is connected. It is connected to the sun gear (11a) of the second stage planetary gear mechanism (1a), and the gear device (1
Place the planet gear support frame (13a) from a) into the inner socket (30),
The housing (2) is connected to the outer socket (40).

The inner socket (30) has a bolt tip (9
1) The nut (92) is engaged with the outer socket (40), and the rotation reaction force generated in both sockets tightens the nut and shears the bolt tip.

[0005]

[Problems to be Solved by the Invention] In the above fastener, the outer socket is as shown by the following calculation.
The torque T3 due to (40) is smaller than the torque T2 due to the inner socket (30). Input torque T1, bolt tip tightening torque T2, nut tightening torque T3, sun gear (11) rotation torque of the first planetary gear mechanism (1) t'1, planetary gear support frame (13) rotation torque t'2, internal gear
The rotational torque of (14) is t'3, the rotational torque of the sun gear (11a) of the second planetary gear mechanism (1a) is t1, the rotational torque of the planetary gear support frame (13a) is t2, and the internal gear (14a). Assuming that the rotation torque of the above is t3 and the efficiency is ignored, the relationship of t'3 = t'2-t'1 ... T3 = t2-t1. T1 = t'1 ...... T2 = t2 ...... T3 = t'3 + t3 ...... Therefore, substituting the equation into the equation, T3 = (t'2-t'1) + (t2-t1) ...... ' In addition, the planetary gear support frame (13) of the first planetary gear mechanism (1) and the second planetary gear support frame (13)
Since the sun gear (11a) of the planetary gear mechanism (1a) rotates integrally, t'2 = t1. Substituting the equation into the equation ', T3 = (T1-t1) + (T2-t1) = T2-T1 ... If the ratio of T2 and T1 is the boosting ratio R, R = T2 / T1 T1 = T2 / R ... Substituting the formula into the formula, T3 = T2-T2 / R = T2. (1-1 / R). The nut tightening torque T3 was smaller than the bolt tip tightening torque T2 by 1 / R, and the nut rotation torque was insufficient. In other words, the bolt tip will be sheared before the nut is tightened to the required torque.
For this reason, when strict tightening is required, after tightening the bolt tip, remove the tightening tool, and follow up tightening only the nut with another tightening tool such as a torque wrench.
It took a lot of time. The present invention discloses a bolt tightening tool that solves the above problems.

[0006]

The bolt fastening tool of the present invention is a manual fastening tool for fastening a bolt having a tip that is sheared when a torque is applied to the tip of the bolt and a nut screwed to the bolt. There are two output gears, an inner socket output gear (3) and an outer socket output gear (4), which are coaxially and rotatably arranged in the housing (2), and shafts of both output gears (3) and (4). An inner socket input gear (5) and an outer socket output gear (4) which are rotatably arranged on an axis B parallel to the center A and mesh directly or indirectly with the inner socket output gear (3) or directly or indirectly. From the two input gears of the outer socket input gear (6) that indirectly mesh, the outer socket (40) connected to the outer socket output gear (4) and engageable with the nut, and the inner socket output gear (3) Protruding outer An inner socket (30) projecting from a shaft portion (31) penetrating the shaft center hole (41) of the racket output gear (4) so as to be engageable with a bolt tip, and the input gear (5) ( The planetary gear mechanism (1) drives the planetary gear mechanism (1), and the planetary gear mechanism (1) inputs the planetary gear support frame (13) to the outer socket input gear (6) and the internal gear (14) to the inner socket input (6). The handwheel (8) is connected to the gear (5) and the sun gear (11), and R ₁ = {(R ₀ +1) / R ₀ } · R ₂ where R ₀ ; of the planetary gear mechanism (1) Tooth ratio of sun gear (11) to internal gear (14) R ₁ ; Tooth ratio of inner socket input gear (5) to inner socket output gear (3) R ₂ ; Outer socket input gear (6) to outer The number of teeth of each tooth is determined so that it becomes the ratio of the number of teeth of the socket output gear (4).

[0007]

[Operation and effect] The input torque t of the planetary gear mechanism, the output torque TA of the internal gear (14), and the planetary gear support frame (1
Regarding the relationship of the output torque TI in 3), TA = R ₀ · t TI = (R ₀ +1) · t when efficiency is ignored. Also, the output torque TB of the manual bolt tightening tool,
TN is TB = R ₁ · TA TN = R ₂ · TI. To tighten the bolts and nuts evenly, use TB
= TN, R ₀ · R ₁ · t = (R ₀ +1) · R ₂ · t, and thus R ₁ = {(R ₀ +1) / R ₀ } · R ₂ . Since R ₀ is already known, R ₁ is replaced by R ₂ (R ₀
If the number of teeth of each gear is selected to be +1) / R ₀ times TB
It is possible to obtain an output torque of = TN. This is applied to a manual bolt tightening tool to reduce the reduction ratio R _{0 of the} planetary gear mechanism (1).
By setting the reduction ratio of R ₂ and R ₁ according to the above, the bolts and nuts can be evenly tightened.
It is possible to eliminate the disadvantage that the axial force introduced is insufficient due to the insufficient tightening force of the nut.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, two output gears, an inner socket output gear (3) and an outer socket output gear (4), are coaxially arranged in a housing (2) in a freely rotatable manner. An inner socket input gear (5) and an outer socket output gear that mesh with the inner socket output gear (3) on an axis B that is parallel to the axis A of both output gears (3) and (4).
The two input gears of the outer socket input gear (6) meshing with (4) are arranged to rotate freely. Outer socket Output gear (4) through tube (42) Outer socket (40)
To project.

A shaft portion (31) is provided so as to project from the shaft center of the inner socket output gear (3), and the shaft portion (31) is provided in a through hole (41) opened in the shaft center of the outer socket output gear (4). An inner socket holding cylinder (32) is provided so as to project at the tip of the shaft portion so as to be freely rotatable. The inner socket holding cylinder (32) is provided with the inner socket (30) concentric with the outer socket (40) by a spline engagement or the like so as to be slidable inside the cylinder and rotatable integrally with the cylinder. Inner socket (30) is holding tube (32)
The spring (33) accommodated in the outer socket (40) urges the spring (33) in the pop-out direction and hits the retaining step (43) formed in the outer socket (40) to prevent the pop-out.

The outer socket (40) has a nut engaging portion.
(44) is formed, and a bolt tip engaging portion (34) is formed in the inner socket (30). The inner shaft input gear (5) is provided with a cylindrical shaft (51) projecting from the axial center thereof, and an internal gear (14) of the planetary gear mechanism (1) is projected from the distal end of the cylindrical shaft. The outer shaft of the outer socket input gear (6) is attached to the cylinder shaft (5
A shaft body (61) penetrating rotatably in (1) is projected, a planetary gear support frame (13) is projected at the tip of the shaft body (61), and the internal gear (13) is formed in the support frame (13). Pivot a planetary gear (12) that meshes with 14).

An input shaft (10) is provided concentrically with the cylinder shaft (51),
The sun gear (11) of the planetary gear mechanism (1) is provided at the inner end of the input shaft (10).
Projectingly engages with the planetary gear (12). A handle mounting portion (10a) is formed at the outer end of the input shaft (10).
Attach the manual handle (8) to a) detachably or integrally.

The planetary gear mechanism (1) and the input gear (5) described above.
The relationship between the number of teeth of (6) and the number of teeth of the output gears (3) and (4) is R ₁ = {(R ₀ +1) / R ₀ } · R ₂ where R _{0 is the} number of teeth of the internal gear (14) / the sun Gear (11)
Number of teeth of R ₁ : Number of teeth of inner socket output gear (3) / Number of teeth of inner socket input gear (5) R ₂ : Number of teeth of outer socket output gear (4) / Number of outer socket input gear (6) The number of teeth is selected so that it becomes a number. Then, fit the nut (92) to the outer socket (40) and the bolt tip (91) to the inner socket (30), and insert the socket (3) from the handle (8) side.
Looking at the (0) and (40) sides, rotate the handle (8) counterclockwise.

As is well known, the rotation of the handle 8 causes the inner socket 30 and the outer socket to pass through the input gears 5 and 6 and the output gears 3 and 4 of the planetary gear mechanism 1. (40)
Transmitted to the inner socket (3
(0) rotates counterclockwise and the outer socket (40) rotates clockwise. When a certain torque is applied to the bolt tip (91), the tip (91) is sheared and the tightening is completed.

When the reduction ratio between the sun gear (11) and the internal gear (14) of the planetary gear mechanism (1) is R ₀ , the input torque t of the planetary gear mechanism and the output torque of the internal gear (14) are shown. The relationship between TA and the output torque TI of the planetary gear support frame (13) is TA = R ₀ · t TI = (R ₀ +1) · t when efficiency is ignored. The output torque TB of the inner socket and the output torque TN of the outer socket are TB = R ₁ · TA TN = R ₂ · TI. To tighten the bolts and nuts evenly, use TB
= TN, R ₀ · R ₁ · t = (R ₀ +1) · R ₂ · t, and thus R ₁ = {(R ₀ +1) / R ₀ } · R ₂ .

That is, if the number of teeth of each gear is selected so that R ₁ is (R ₀ +1) / R ₀ times R ₂ , the output torque TN of the outer socket and the output torque TB of the inner socket are balanced. In the present invention, R ₁ is replaced by R ₂ (R ₀ +
1) / R ₀ By selecting the number of teeth for each gear, the bolts and nuts can be evenly tightened. Therefore, the tightening force of the nuts is insufficient and the introduction axial force is insufficient. It is possible to eliminate the drawback.

Next, an example of actual numerical values will be shown. R ₀ = 4 (reduction ratio of a general planetary gear mechanism) If the number of teeth of the outer socket output gear (4) is 30 and the number of teeth of the outer socket input gear (6) is 33, then R ₁ = (4 + 1) / 4 ・ 30 /33=1.13363636
36. Under the condition that the axial distance between the inner socket output gear (3) and the inner socket input gear (5) matches the axial distance between the outer socket input gear (6) of the outer socket output gear (4), the inner socket output Gear (3)
The number of teeth of the inner socket input gear (5) and the number of teeth of the inner socket input gear (5) may be selected so that R ₁ may be an approximate value of 1.136363636.

Now, the inner socket output gear (3) has 34 teeth and the inner socket input gear (5) has 30 teeth.
And then when the the value of R _1, 'is calculated as, R _1' R ₁ a = 34/30 = 1.133333333. The difference between R ₁ and R ₁ ′ is R ₁ / R ₁ ′ = 1.00267, and the bolts and nuts can be evenly tightened with a difference of about 0.3%. Incidentally, in the conventional manual bolt tightening tool, a difference of about 20 to 30% occurs.

An idle gear (not shown) is interposed between the inner socket input gear (5) and the output gear (3) and between the outer socket input gear (6) and the output gear (4).
In this case, the rotation direction of rotation of the handle (8) can be matched with the rotation direction of the nut. The present invention is not limited to the configuration of the above embodiment, and various modifications can be made within the scope of the claims.

[Brief description of drawings]

FIG. 1 is a sectional view of a fastener.

FIG. 2 is a conceptual diagram of a fastener.

FIG. 3 is a conceptual diagram of a conventional example.

[Explanation of symbols]

 (1) Planetary gear mechanism (3) Inner socket output gear (4) Outer socket output gear (5) Inner socket input gear (6) Outer socket input gear (30) Inner socket (40) Outer socket

Claims (1)

[Claims] 1. A manual tightening tool for tightening a bolt equipped with a tip and a nut screwed to the bolt, which is sheared when a torque over a certain level is applied to the tip of the bolt, and is coaxial with the housing (2). Inner socket output gear (3) and outer socket output gear arranged to rotate freely
Two output gears of (4) and two output gears (3) (4) are arranged rotatably on an axis B parallel to the axis A of the output gears (3) and (4), either directly or indirectly to the inner socket output gear (3). Two input gears, the inner socket input gear (5) and the outer socket output gear (4), which mesh directly or indirectly with the inner socket input gear (5) and the outer socket output gear (4), and the outer socket output gear (4) are connected. The outer socket (40) that can be engaged with the nut, and the inner socket output gear (3) protrudes from the inner socket output gear (4) and the shaft portion (31) that rotatably penetrates the shaft center hole (41) of the outer socket output gear (4). The planetary gear mechanism (1) is provided with an inner socket (30) that can be engaged with a bolt tip and a planetary gear mechanism (1) that drives the input gears (5) and (6). (13) to the outer socket input gear (6) and the internal gear (14) to the inner gear. The socket input gear (5), manual handle to the sun gear (11)
And in tandem with _{(8), R 1 = {} (R 0 +1) / R 0} · R 2 where R _0; teeth of the sun gear (11) and the internal gear (14) of the planetary gear mechanism (1) Number ratio R ₁ ; Tooth ratio of inner socket input gear (5) and inner socket output gear (3) R ₂ ; Tooth ratio of outer socket input gear (6) and outer socket output gear (4) A manual bolt fastener that determines the number of teeth in each tooth.